Bearded irises have few problems , but there are a pair common ones that may snip up : iris woodborer and foliage spot . They do n’t obliterate your plants decently away but weaken them over time until they at long last die . One practice that keep bewhiskered irises healthy is getting free of the leafage in later fall . reduce back to the rhizome or tug away dried or hackneyed - look leaves and glow , bury or send them off in the trash , peculiarly if you ’ve noticed any problem over the raise time of year .
Iris borer
Iris stone drill is cause by the iris borer moth ( Macronoctua onusta ) that lay egg in leaf bedding in fall . When the larvae hatch in spring , they quickly discover refreshing new iris foliage to eat up , gradually working their direction down to the rhizome and finally out into the soil to pupate . If you mark brown streaks or collapsed foliage ( or both ) , apprehend up the rhizome and check off for a small caterpillar like the one in the picture above . Pesticides are n’t usually effective here so expend fall cleanup to short circuit the borer ’s life cycle . After vote out the catepillar , examine spare the works by cut away the rotten parts and dipping it in a solution of one part whitener to four parts water supply . Let it dry for a couple of days and replant .
Leaf spot
Your fountain iris show does n’t have to be over in a flash . Troubleshoot when needed and you could enjoy the color for calendar week .
